confused with cin in C++

[John Ruan]

This is a small program in C++. I want to try to type in real number instead
of integer to see how the program runs.
And I am confused. If I input integer for both variables, the program runs
fine. But if I input a real number for the height (like 68.2), the second
cin doesn't work at all!!

I expected any real number will be truncated and that is my only
expectation. But it seems that there are other problems. Can anybody try it?

#include <iostream>
using namespace std;

int main(void)
{
const double INCHES_PER_METER = 39.37;
const double POUNDS_PER_KG = 2.24;

int height;
int weight;

cout << "METRIC CONVERTER" << endl << endl ;
cout << "Enter your height in inches " ;
cout << "(No fractions, please!) : " ;
cin >height;

cout << "Enter your weight in pounds" ;
cout << "(No fractions, please!)" ;
cin >weight;
cout << endl ;

double metric_height = height/INCHES_PER_METER;

double metric_weight = weight/POUNDS_PER_KG;
cout << "Your height is " << metric_height << " meters." << endl;
cout << "Your weight is " << metric_weight << " kilograms." << endl;

return 0;
}

[Bo Persson]

John Ruan wrote:

This is a small program in C++. I want to try to type in real
number instead of integer to see how the program runs.
And I am confused. If I input integer for both variables, the
program runs fine. But if I input a real number for the height
(like 68.2), the second cin doesn't work at all!!

The input is originally text, which is scanned for digits that can be
part of an integer. The first input reads a 6 and an 8, and gives you
the number 68.

When you try to read a second integer, the first character found is a
period, which is an error for integers. You get no number.

Bo Persson